Add optional auto scrolling of the container during sort

[tumispro]

This wasn't easy, but I think I got it working pretty robustly 🙂

Functionality:

• Auto scroll the container (or window if applicable) when dragging items near the edges
  - Prevent default browser scrolling (when auto scrolling is disabled), inspired by @phoebejaffe's solution (Autoscroll #4 (comment))

This is a work in progress as it doesn't (and might never) support horizontal scrolling and it still needs to be tested thoroughly. It works pretty nicely so far for a few implementations I did myself though.

Update: supports both vertical as well as horizontal auto scrolling now. Worked smoothly in all my tests:

• Vertical list within window
• Vertical list within container
• Vertical list within an element within a container (nested)
• Horizontal list within window
• Horizontal list within container
• Horizontal list within an element within a container (nested)

[ValentinH]

Thanks a lot for taking the time to work on this. I'll try to carefully review this later this evening.
After quickly having a look, I don't think that when autoScroll is false, we should disable the scrolling of the parent container. This can be done outside of the lib if people have the need but it could create issues for existing users of the library.
One case I have in mind is the whole body shifting to the right due to the scrollbar being removed.

[tumispro]

Ah you are probably correct. I will remove that behaviour entirely tonight or tomorrow if I find some more time. I was considering to enable it when autoscrolling is enabled, so that the dragged item doesn't show above the scrollbar when the scrollable element is a container, but I guess that isn't too much of an issue as showing the scrollbar is more useful/important.

Take your time and thanks for your quick response!

[tumispro]

Removed the disabling of the default browser scroll behaviour

[socket-security]

No dependency changes detected. Learn more about Socket for GitHub.

👍 No dependency changes detected in pull request

[ValentinH]

I've updated the vertical list story to show the new feature.

[tumispro]

Was testing a bunch of different implementations and the lack of horizontal scroll support stung me, so added that as well. Wasn't too big of a change compared to the vertical auto scroll 🔥

[ValentinH]

It looks great! I've updated the other stories.

Can I go ahead and merge this?

[tumispro]

I feel it's functionally complete and it passed all the different implementation tests I did. As it's optional and off by default releasing it should be fine imo. Thanks for your swiftness as always!

[tumispro]

Tested some more and fixed a small bug where it stopped working when an axis was locked (axes check was swapped)

[ValentinH]

I'll do a last review and merge this tonight 👍

[ValentinH]

Published as react-easy-sort@1.8.0 🎉

Thanks again @tumispro !!